Record cutting device



May 13, 1941. G. SILBER ErAl.

RECORD CUTTING DEVICE Filed April 22, 1939 f4 ATTORNEY.

Patented May 13, 1941 UNITED s'rras ear OFFICE 1 Claim.

This invention relates to a device for inscribing soundwaves, e. g. by acutter on a record,

from which the sound may be reproduced ad libitum. The cutter comprisesa cutting tool and I-means for imposing sound waves upon the tool.

Att-he present'state of the art an electrical actuation of vthe cuttingtool is in particular favor, e.g. bya solenoid or electroma-gnet of acircuit `.which is adapted for the transmission of sound wavestranslated into electrical impulses. Such circuit comprises a-source ortransmitter of an ,electrically expressed sound, such as a microphone, aradio or a public'address system, -lends itself readily to modulation,-ltration and volume adjustment of and is suited to be electrically.connected to the receiver incorporated in the cutter of a recordcutting device.

At the present state of the art such a record vcutting device "must be aprecision instrument,

because an extremely delicate cutting adjustiment .of the cutting toolis required in relation -to 'the record, which is, for instance, anacetate layer reinforced by a metallicbacking. The carvriage`orniounting of the cutting tool must move relatively to therecord,fand'the parts effecting this movement must be made and mustperform -withextreme accuracy, in order not `to impose, :and yas Vamatter of fact in order to eliminate, lany extraneous component ofmovement ofthe .cutting-tooLwhich component Would distort or .otherwiseimpair the fidelity ofthe sound track produced.

It .is a .principal object of this invention `to provide for a feedingmechanism of the order just referred to, which will not rely upon anextreme *accuracy lof v,the parts `and Vwill therefore beieconomical inmanufacture and maintenance, -ands'till permits a movement of thecutting 'tool in :faithful and exclusive conformity with the soundwaveimposed thereon.

At thepresent state ofthe art it is desirable rtoprovide-fora-recordcutting device which can She lused in connection with a soundreproducing vdevice adapted -for translation vof the cut record .intosound, such as a gramophone or phonograph. Irl-such cases itlis-expedient to'couple -the :record cutting device, preferablyydetachably, `tozthe'record carrier,-e. gfa turntable, in order toestablishthe proper relationship between the .crossieedzofthe cutter andthe movement,-e. g. rotationof the record to .be cut.

Where in the manner just suggested, and more .particularly for practicalreason, therecordcutting device is detachably Acoupled with or con-LVnectedtothe record carrier, additional dangers arise concerningaccurate performance Aof the cutting device. The cutting device, or partthereofl is handled asa loose-part, e. g. a swing arm, which mayreadilyget out of alignment or adjustment, the cutting device may be`improperly or carelessly coupled or connected to the record carrier, orthe arrangement may Ynecessitate that the record cutting device connects.to

the record carrier by way of therecord, and may thus suffer if therecord or the record carrier is eccentric, uneven in thickness or Warpedas it will `loe the case in thecustomary arrangement, where the cuttingdevice is depositedat one end, for purpose of `mechanical drive, vupon aArecord deposited upon a turntable. It is readily understood, that underthese circumstances the most accuratelyconstructed and vperformingcutting-device may fail to voperate properly, when itis coupled to asurface which wabbles, is unyeven, or otherwise causes eccentricity;Under these circumstances the instant invention, as suggested above,assures good performance; in

Iother words, correct guidance, suspension'or control of the cuttingtool is to be obtained, v.disre- -garding any lack of `trueness andalignment -of the operating mechanism.

These and other objects of the invention are generally obtained, inaccordance vwith the instant invention, by a novel suspension. andmounting of the cutter, and will be Yexplained hereinafter at greatdetail in connection with the description of a specific embodiment-ofthe invention and with the accompanying drawing, the description anddrawing being however exclusively submitted in illustration, and not forthe purpose of limitation, of the instant invention.

In the drawing:

Fig. 1 is the top view of an embodiment of this invention, which, by wayof example, is adapted for use in connection with a phonograph.

Fig. 2 is a corresponding front-view, showing the embodiment at asmaller scale, part o-f the phonograph beingV schematically indicated.

Fig. 3 shows a cross-section of the embodiment taken at a levelindicated by way of dotdash lines, arrows and the numeral 3 in Fig. 1.This detail View serves in particular to illustrate the arrangement of acarrieron which the cutting tool is suspended.

Fig. 4 is a similar cross-sectioned detail View taken at another levelpointed out by the numeral 4 and arrows in Fig. 1, and serving inparticular to illustrate the manner in which the cutter is suspendedupon thecarrier.

Fig. is a detail bottom View of the carriage, directed in particular toan illustration of the jaw, by way of which the carriage engages uponthe feed screw of the cutting device.

Similar numerals refer to similar throughout the various views.

An embodiment Aof the kind shown in the drawing has, for instance, astand II from which vertically arises an arbor I2. This stand II isshown to be xedly mounted upon the top board IIJ which serves as apartition in a phonograph and extends on top of the mechanism and belowthe turntable 9. Upon the stand I I, which is thus arranged alongside ofa turntable 9 on top of the phonograph, an arm I3 is swingablyfulcrurned, so that the said arm I3, by way of a handle I4 arranged atthe end thereof, may be swung over the turntable and may be depositedthereon, the said arm carrying for such purpose a driving disc I5 whichmay frictionally or xedly, e. g. by way of pins extending into holes I6in said disc I5, engage upon a record I'I deposited the baize coveringI8 of the turntable 9, or, by way of said holes I6, upon pins extendingfrom turntable 9 through record I'l.

When the swing arm I3 is in the horizontal position shown in Fig. 2, theshaft I9 of disc I5 extends preferably parallel to the arbor I2 on standII, and the shaft and arbor are spaced apart at a predetermineddistance, which corresponds to the distance, at which the stand II ismounted from the axis of turntable 9 of the phonograph.

From the operative position of the record cutting device shown in Fig. 2the said device may be swung laround the arbor I2 into an inoperativeposition, in which it fully clears the turntable 9 and is extendedalongside of said turntable. If, for instance, the turntable is arrangedin a square box upon the square board IB', and the stand II is mountedupon a diagonal of said box, the turntable may have to be swung through45 from the operative position of Fig. 2 into an inactive positionalongside of turntable 9. In order to permit the disc I 5 to be liftedolf the turntable or off the record I'l arranged thereon, the arm I3should also be swingable around a substantially horizontal axis whichcrosses or passes close to the vertical axis of arbor I2 and which isdisposed substantially in a plane with the bottom face of disc I5. Forsuch purpose the arm I3 is shown to comprise a bracket element 33 withlugs 2|, which are journalled upon a hinge pin 20, a pair of nuts 22serving to position said arm endwise upon the hinge pin 20 against aface of the head 23 at the other end of hinge pin 20.

The head 23 of the hinge pin 20 is provided with a bore lextendingsubstantially at' right angles to the axis of hinge pin 29, said headbeing journalled by way of said bore upon a sleeve 24 which carries atits upper end the knurled ange 25, whereas it is provided with an outerthread 26 at the lower end. Thread 26 serves to receive the nut 2l,which, by way of a set screw 28 may be iixedly allocated upon the sleeve24 in a position in which the head 23 is rotatably but endwise xedlyallocated upon said sleeve.

A fiat 29 may be provided upon one side of the arbor I2, in order tofurnish a space, upon which a set screw 30 in the knurled flange 25 maybe engaged at a preferred level upon the said arbor i2. Since theswinging arm I3 thus is vertically adjustably fulcrumed upon arbor I2 byway of the sleeve 24, said arm I3 may be adjusted to be in thehorizontal position shown inv Fig. 2, when parts the disc rests upon theturntable or the record. It is more particularly desirable, that arm I3extend at right angles with the axis of turntable 9, or parallel withthe line along which the record cutting operation takes place, when therecord cutting device is in the operative position shown in Fig. 2.

When reference was had hereinbefore, generally, to an arm I3, referencewas had thereby primarily to a portion thereof, which serves as a levelguide for the carriage 3l. Such a guide portion provided by a smoothspacing rod 32 which is shown to be xedly engaged upon and positionsrelatively to each other the bracket element 33 to the right, whichcomprises the lugs 2! referred to above, and the element 34 to the left,which carries the handle I4 and the forked portion I5 of which the discI5 is journalled by way of the shaft I9, collar 36 of shaft I9 servingto retain disc I5 in rotatable suspension upon said element 34.

In order to forestall any risk that the elements 33 and 34 be twistedrelatively to each other by way of torsion of the spacing rod 32, suchelements are reinforcedly interconnected by a flat bar 2l, which isspaced relatively to the spacing rod 32 and is disposed substantiallynormal to a plane extended through the axis of the spacing rod at thenearest point between the said at bar and rod.

Flat bar 31 also serves as a back rest for the carriage 3l, when suchcarriage is swung around the rod 32 back into an inactive position. Orsaid bar 31 offers a means upon which a resilient catch 38 extendingfrom carriage 3I may be engaged, e. g. slid under, thus releasablyretaining the carriage 3l in a reclined, inactive position, although thearrangement of the weight of said carriage, and more particularly thecounterweight 39 at the front thereof, tend normally to swing saidcarriage in counter-clockwise direction around the rod 32 intoengagement with feed screw 4I).

In the prior art the feed screw, i. e. its accuracy as a machineelement, its alignment in respect to the guide means of an arm such asI3, and above all the question whether it was running true, presented adecisive factor concerning the value of the record cutting device,because this governed the quality of the cut produced on the record. Italso should be taken into purview, that a feed screw must extend over acomparatively wide gap without any support, so that it may readily runout of true, or sag, or its trueness may be impaired by carelesshandling.

Of course there is no particular diiiculty in providing an accuratepitch or lead and the correct form of thread on a feed screw. But inaddition to these features the prior art found it an indispensableprerequisite, that the feed screw ran true under all circumstances, andsuch an ideal object is difcult to carry out; therefore the necessitythereof has been substantially avoided by this invention. A screw beingselected to be of correct pitch and shape of thread and of sufcientstrength not to sag, is hung, between centers so to speak, into therigid frame provided by the spacing rod 32, the flat bar 31 and the endelements 33 and 34. Opposite ends of the screw are for such purposeshown to be engaged upon balls 4I. These balls 4I are socketed in theends of headless screws 42, and these headless screws 42 may be adjustedin axial alignment with each other in the elements 33 and 34 by way oflocknut 43 engaged thereon, so that the screw 40 is rotatably suspendedwithout play in the arm- I3, and extends substantially parallel withthespacing rod 32. v l

For purposes of a drive feed screw 4i!r carries near one of its ends theworm Wheel 44, and worm wheel 44 is engaged by worm 45 mounted upon theshaft I9 in the forked portion 35 of element 34.

Around the hub 45, which extends from the forked portion 35 down ontoVthe disc I5 an auxiliary disc 41 is spacedly assembled with the disc I5,such arrangement presentingva spool and serving for diverting orcollecting shavings thrown up by the cutter 52 engaged upon the recordI1, so that such shavings do not enterk upon the worm drive nor upon thebearings by way of which the worm is journalled upon the element 34.

The carriage 3| is slidably fulcrumed upon the spacing rod 32, e. g. byway of two spaced lugs 48 and 49. A lug 53, which is connected by way ofbracket I to and supports the cutter 52, is endwise engaged between saidlugs 48 and 49, so that it must partake in the movement of the carriage3| in the direction of the spacing rod 32, but the cutter 52 may stillbe swung on rod 32 in a plane normal to said rod independent of theswinging of the carriage 3|. This independently swingable cutter 52 isresiliently suspended on the carriage 3| by way of a coiled tensionspring 54,

which extends from the bracket 5I connecting lug 5|) with cutter 52 to aheadless screw 55. Screw 55 is non-rotatably slidably accommodated in anextension 51 of the carriage 3| and transmits, by way of a knurled nut58, the reaction of tension spring 54 to extension 51. Rotation of theheadless screw 55 in extension 51 is prevented by providing flats on oneor more sides of the screw 55 and by accordingly contracting the openingin the extension 51, in which that screw is accommodated.

The cutting tool 53 is mounted to extend from the bottom of the cutter52, and the electric mechanism in cutter 52 for actuating cutting tool53 is to be connected by the flexible leads 59 extending from cutter 52to a suitable source of electrically converted sound wave. I

The distance to which the cutter 52 depends in counterclockwisedirection from the carriage 3| is determined and adjusted by the knurlednut 58. l

If the instant cutting device were carried out in accordance with theteachings of the prior art,

the carriage 3|, would directly though detachably engage upon the feedscrew 4B, so that any throwing caused by any eccentricity of the feedscrew 4|) would cause the carriage to rock or sway and such movementwould be transmitted to the cutter 52 by way of the means 54, 55, 55,51, 58 suspending the cutter upon the carriage.

But such rocking and swaying is prevented in accordance with the instantinvention, even though the feed screw may run slightly off center or beuneven, by providing a oating suspension in place of a rigid engagementof the carriage upon the feed screw.

In such a floating suspension the carriage is rigidly coupled to thefeed screw in the direction of the axis of the feed screw, so that thecarriage is predeterminedly and correctly propelled by rotation of thescrew in order to produce evenly spaced convolutions of a spiral orhelix upon the record. Whereas the carriage is only loosely coupled ontothe feed screw in all other directions, i. e., radially to the feedscrew,

and does therefore not participate in any rocking movement of saidsorew.Thisis provided in the instant improvement by predeterminedly weightingthe carriage, so that a jaw 60 is pressed intolrm engagement with thefeed screw 40, and so that the said jaw is positively fed in thedirection ofthe axis of the screw by reason of the engagement of the jawon the carriage. The weight of the carriage may be supplemented for thispurpose by a suitably dimensioned and allocated counterweight 39, but adirect reaction of such weight to'any off-center movement of the screwis prevented by interposing between the carriage and the jaw a fullybalanced cushioning medium, such as a spring.

For such purposes the carriage 3| is provided for a clearance serving asa cage loatingly retaining the jaw 60. The jaw is provided upon oppositesides and on opposite ends with flange like extensions 62 and 63, whichby way of parallel surfaces extending normal to the axis of the feedscrew engage upon corresponding surfaces upon opposite sides of thecarriage, for instance upon the opposite ends of the stops 64 extendingin the front and in the back into the clearance 6| of a carriage. Thejaw 'itself is predeterminedly spaced from the front and back walls ofclearance 6I.

Jaw 6U represents half a nut meshing upon the thread of feed screw 40and on the side opposite to the threaded groove a pin 66 extends fromthe jaw and is swivelled, e. g. loosely guided near its far end upon thecarriage 3|. For such purpose a hub 61 extends up from the carriagewhich has a clearance opening commodiously accommodating the said pin 6Band the compression spring surrounding said pin and carries on itsupper, threaded end a knurled bushing 68. Bushing 68 closes the upperend of hub 61, except that it has a central opening which accommodateswith play the pin 66 extending therethrough. By way of a washer orsleeve 59, which may t pin 6B, but which should have play in bushing 68,the compression spring 65 reacts between bushing 63 as part of thecarriage 3| and the jaw 60.

When carriage 3| is swung out of engagement with feed screw 40 and is,for instance, engaged in a reclined position by way of the catch 38 uponthe flat bar 31, the compression spring 65 will depress the jaw into alowest position, in which it rests upon the stops 64. Under thesecircumstances the cutter 52 will also be reclined, bracket 5| restingagainst the top section of the carriage 3|, which interconnects thespaced lugs 48 and 49. When the arm I3 is thus swung back from theoperative position shown in Fig. 2, disc I5 resting in operativeengagement upon a record I1 superimposed upon the turntable 9 of aphonograph and sleeve 24 being adjusted at such height on arbor I2 thatthe smooth spacing rod is substantially parallel to the surface ofrecord I9, then the carriage 3| may be slid on rod 32 to a positionnearest to element 34, and the carriage 3| is swung forward from itsIreclined position. While the carriage 3| is thus swung to the front, thecutter 52 will also drop forward, unless it is intercepted by the handof the operator, onto a stop 13 provided for said cutter 52 upon thecarriage 3|. During the frontward movement of the carriage 3| the jaw6|) will strike and rest upon the feed screw 40 and then the stop 54will be lowered from jaw 60 together with the carriage until thecompression of spring 55 counteracts the weight of the carriage and ofcounterweight 39. The carriage will ind its own level in reaction to thepressure of spring 65, such a position being approximately indicated inFig. 3 of the drawing. Now the cutting tool 53 extending down from thecutter 52 has also come into abutment upon the record l1, so that thecutter has been lifted off the stop T0. The carriage 3l has in themeantime assumed an average position relatively to the feed screw 40,such average position approximating that indicated in Fig. 3, and thepressure, at which the cutting tool 53 `engages upon and in the recordI1 may be adjusted by way of rotation in clockwise or counter-clockwisedirection of nut 58. Thereafter the cutter 52 or the carriage 3ltogether with the cutter 52 may be lifted ad libitum out of anengagement with the record or out of engagement with the record and thefeed screw, respectively.

But when the parts are in the adjusted position of Fig. 3 and theturntable 9 is in rotation, any sound arriving at the cutter 52 by wayof the leads 59 will be inscribed by the cutting tool 53 onto the recordI1, while the cutting tool describes a spiral path upon the rotatingrecord I1 by virtue of the cross feed mechanism of the record cuttingdevice described. It will be noticed that the feed screw 40 may runoff-center, but that the carriage 3| will oat while it is positively andaccurately advanced in the feed direction.

Having thus described our invention in detail, yet we do not wish to belimited thereby, except as the state of the art and the appended claimsmay require, for it is obvious that various modications and changes maybe made in the form of the embodiment of our invention, withoutdeparting from the spirit and scope thereof.

What we claim is:

In a record cutting device, in connection with a feed screw and acarriage to be moved by said screw, a jaw adapted to mesh with rsaidscrew when moved onto said screw in a predetermined direction, tensionmeans reacting between said carriage and jaw in said direction, a rodextending from said jaw in said direction, a guide means on saidcarriage loosely accommodating said rod so that said jaw may swingrelatively to said carriage substantially in an arc around said guidemeans at right angles to the axis of said screw, and guide means xedlyallocating said jaw upon said carriage in the direction of the axis ofsaid screw.

GEORGE SILBER. VICTOR SILBER.

